text: /*
   * Copyright (c) 2003-2005 The Regents of The University of Michigan
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are
   * met: redistributions of source code must retain the above copyright
   * notice, this list of conditions and the following disclaimer;
   * redistributions in binary form must reproduce the above copyright
   * notice, this list of conditions and the following disclaimer in the
   * documentation and/or other materials provided with the distribution;
   * neither the name of the copyright holders nor the names of its
   * contributors may be used to endorse or promote products derived from
   * this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
   * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
   * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
   * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
   * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #include <unistd.h>
  
  #ifdef __APPLE__
  #include <mach/mach_init.h>
  #include <mach/shared_region.h>
  #include <mach/task.h>
  
  #endif
  
  #include "base/hostinfo.hh"
  
  #include <cctype>
  #include <cerrno>
  #include <cmath>
  #include <cstdio>
  #include <cstdlib>
  #include <cstring>
  #include <string>
  
  #include "base/logging.hh"
  #include "base/str.hh"
  #include "base/types.hh"
  
  using namespace std;
  
  string
  __get_hostname()
  {
      char host[256];
      if (gethostname(host, sizeof host) == -1)
          warn("could not get host name!");
      return host;
  }
  
  string &
  hostname()
  {
      static string hostname = __get_hostname();
      return hostname;
  }
  
  uint64_t
  procInfo(const char *filename, const char *target)
  {
      int  done = 0;
      char line[80];
      char format[80];
      long usage;
  
      FILE *fp = fopen(filename, "r");
  
      while (fp && !feof(fp) && !done) {
          if (fgets(line, 80, fp)) {
              if (startswith(line, target)) {
                  snprintf(format, sizeof(format), "%s %%ld", target);
                  sscanf(line, format, &usage);
  
                  fclose(fp);
                  return usage ;
              }
          }
      }
  
      if (fp)
          fclose(fp);
  
      return 0;
  }
  
  uint64_t
  memUsage()
  {
  // For the Mach-based Darwin kernel, use the task_info of the self task
  #ifdef __APPLE__
      struct task_basic_info t_info;
      mach_msg_type_number_t t_info_count = TASK_BASIC_INFO_COUNT;
  
      if (KERN_SUCCESS != task_info(mach_task_self(),
                                    TASK_BASIC_INFO, (task_info_t)&t_info,
                                    &t_info_count)) {
          return 0;
      }
  
      // Mimic Darwin's implementation of top and subtract
      // SHARED_REGION_SIZE from the tasks virtual size to account for the
      // shared memory submap that is incorporated into every process.
      return (t_info.virtual_size - SHARED_REGION_SIZE) / 1024;
  #else
      // Linux implementation
      return procInfo("/proc/self/status", "VmSize:");
  #endif
  }
  